New Construction Acoustic Design & Consulting


I need a professional consultant to work with my architect to help build as perfect a listening room over my garage as possible. RIVES is one possibility but I don't want to spend 10K just for the consulting work. I would like to build in as much sound isolation and room treatment as possible like that done for this person:
http://www.positive-feedback.com/Issue16/lavigneroom.htm--

Could I use ASC as a primary consultant and RIVES for after the room is built to do the final touch ups and room treatment? They only charge $100 for the engineer to help render sketches and make suggestions for the contractor.

acousticsciences.com

I would need detailed plans so that the architect would know how to impliment the built-in bass traps etc. I would need help with the specifics of window and door selection (materials) and placement, room dimensions, ceiling slope, floating floor, isolation etc... Please also see the list of ideas below. RIVES charges a fortune to render drawings based on a computer modeling system. I am not sure all of that makes sense until after the room is built, furnished and then tested, but certainly it is advantageous to build in as much acoustic isolation and treatment as possible from an aesthetic and cost perspective. Please comment on some of the suggestions below:

Room sizes

13X21X8 Feet
14 X18X8 Feet

windows o.k.
According to Dave Wilson

1. pitch ceiling height lower over speakers, higher over listener
2. Build bass traps into the wall
3. Corner loaded bass traps
4. Bass trap all four vertical corners and the ceiling perimeter corner with a soffit bass trap
5. Room dimensions:
Must over-size room by minimum of 6 inches walls, floor, and ceiling to allow for buildouts for acoustic treatments and sound isolation
A. 13-15 feet wide by 15-23 feet long
B. Room height 7-9 feet
must account for additional height of "floating floor"
C. Wall/stud resonance treatment and constrained layer damping: 1. Sandwich two layers of sheetrock. ? Gyproc Soundbloc 1.5 soundproofing plasterboard 2. Suspend sheetrock off studs by screwing into resilient metal fir strips called "z-metal" or "RC-1" 2. Visco damping material {1/16 " thick double sided adhesive visco-elastic sheet} is applied between the z-metal and the first sheet rock layer and a second visco-elastic sheet between the first and second layers. In place
of double sided adhesive visco-elastic sheet, can 100% glue to both sides a layer of sound board {firtex or celotex}. ? Staggered studs. The ceiling must be treated the same way.
D. Locate entry door behind the listner but on a SIDE WALL {nowhere near the speakers since the door will raddle} NOT ON A BACK WALL AND not flush to the corner and at least 2 feet from the corner. Door cannot rattle? Heavy acoustic door/frame?
E. Windows are very tympanic and should be avoided. Tall narrow windows are best.
Must not use standard thermal type instead use 2 layers of thick laminated glass [like that used for glass shelving in stores] separated by at least 4 inches of air space. The air space must be vented into the wall cavity. Set the glass into a bed of visco-elastic damping material. The glass sheets should be of different thicknesses.
F. Lighting should be subdued, indirect, and dimmable. Do not use standard wall dimmers since they will often hum or buzz. Use a variable voltage transformer. Consider low voltage lighting. Do not use ceiling cans, they rattle. The best light has a ceiling bezel and lens of thick rounded glass. Consider creating a false ceiling to hide projector, cabling, HVAC
ventilation big problem if room needs to be airtight to insure adequate sound isolation and room damping from the rest of the house
G. Address side wall, rear wall, and ceiling reflections which are determined by speaker placement. Room dimensions must account for acoustic panels
dbk
My thought is that with the amount of $ you are going to spend on the construction of this room, and the kind of equipment I would guess you would go for, the $1K fee is dirt cheap, esp. if it can help you avoid ONE mistake.
I would prefer the 13 x 21 x 8 ft dimensions.

A lot of the points you mention above are good and definitively should be considered in the new room.

Assuming that the room is built well with all the basic elements(many of which you already mention), you may not need any special acoustic treatments.

I say that because based on my experience, speaker placement plays a far, far more significant role that room acoustics and treatments. In fact, I think it was Robert Harley of TAS who said a few months ago that proper speaker placement provides far greater benefit than any room acoustics. Or something like that.

Some to many say room acoustics makes up about 80% of the sound you hear. I'd guess it's probably more like 20% with the room/speaker interaction making up perhaps 50% of the ultimate sound you hear. I'm guessing but I'll bet it's a lot more accurate than the 80% rule.

One thing I would consider adding to your list is a beamed ceiling where the beams are spaced perhaps no more than 3 or 4 ft apart starting at the front (behind the speakers) and then perhaps every 3ft going toward the rear of the room.

Oh yeah, when it comes to furnishing you might consider heavy clothe/cushioned listening chairs or sofas, leaving the leather furniture, tables, floor lamps, etc. for another room. If you need a coffee table of sorts, you might consider a larger cushioned ottoman instead.

-IMO
I agree on the $1k fee, yes i know you said $10k. I just used Richard on a 12 x 17 room and the $900 he charged was a very "sound" value. If you want him to be able to charge less do some work for him. Fill out his form YOU get from his web site and list all the material you plan on using. The architect you are already paying should tell you that. Draw out the room and specify a level one job. Show each revision from Rives to your architect for the ok and then send it back to Richard. If you want to save you gotta work!